chore: rename `Complete` to `CompleteColor`

[meowgorithm]

This revision renames Complete to CompleteColor and CompleteFunc to CompleteColorFunc. Out of context, Complete is too ambiguous, particularly because the scope of Lip Gloss is beyond color.

[meowgorithm]

@aymanbagabas I think LightDark is fine as-is because it implies color (or, at least, luminance). I'm fine if Complete is something other than CompleteColor but we need something beyond Complete to make it more specific.

[lrstanley]

CompleteColor to me still doesn't convey the full purpose/intent, only helping convey that it's related to a color. Thoughts on something like ResolveColor (ColorResolverFunc for the func type)? "resolve" indicates it is the final result of some computed logic, and that might hint that a user can hook into that resolution logic to change it.

Some other thoughts, in case we're still not 100% on anything:

• AdaptiveColor
• DownsampleColor